A plain bearing has two components that have bearing surfaces in mutual sliding engagement with each other and that define a load zone between the components. For example, one component of a spherical plain bearing is an outer ring having a concave bearing surface and the other component is an inner ring having a convex bearing surface. The inner ring is disposed within the outer ring and the rings are sized and configured so that their bearing surfaces are in sliding engagement with each other. The inner ring and the outer ring have seating surfaces for connecting to structures whose relative motion is to be accommodated by the bearing.
Commonly, bearings are made from steel. To extend the life of the bearing, it is known to provide lubricant in the load zone to reduce wear on the bearing surfaces.
Rotary wing aircraft, such as helicopters, provide unique environments for the use of spherical plain bearings due to the harsh conditions helicopters impose on the bearings and the general practice of providing bearings of reduced weight.
Based on the foregoing, it is the general object of this invention to provide a plain bearing that improves upon, or overcomes the problems and drawbacks of, prior art plain bearings.